Files
openlayers/src/ol/renderer/dom/domtilelayerrenderer.js
2012-10-26 11:25:26 +02:00

292 lines
8.0 KiB
JavaScript

goog.provide('ol.renderer.dom.TileLayer');
goog.require('goog.asserts');
goog.require('goog.dom');
goog.require('goog.events');
goog.require('goog.events.Event');
goog.require('goog.events.EventType');
goog.require('ol.Coordinate');
goog.require('ol.Extent');
goog.require('ol.renderer.dom.Layer');
/**
* @constructor
* @extends {ol.renderer.dom.Layer}
* @param {ol.renderer.Map} mapRenderer Map renderer.
* @param {ol.layer.TileLayer} tileLayer Tile layer.
* @param {!Element} target Target.
*/
ol.renderer.dom.TileLayer = function(mapRenderer, tileLayer, target) {
goog.base(this, mapRenderer, tileLayer, target);
/**
* @type {Object}
* @private
*/
this.renderedTiles_ = {};
/**
* @type {number|undefined}
* @private
*/
this.renderedMapResolution_ = undefined;
/**
* @type {number|undefined}
* @private
*/
this.renderedZ_ = undefined;
/**
* Map of tile keys loading at the currently rendered z.
* @type {Object.<string, ol.Tile>}
* @private
*/
this.loadingTiles_ = {};
};
goog.inherits(ol.renderer.dom.TileLayer, ol.renderer.dom.Layer);
/**
* @inheritDoc
* @return {ol.layer.TileLayer} Layer.
*/
ol.renderer.dom.TileLayer.prototype.getLayer = function() {
return /** @type {ol.layer.TileLayer} */ goog.base(this, 'getLayer');
};
/**
* Get the pixel offset between the tile origin and the container origin.
* @private
* @param {number} z Z.
* @param {number} resolution Resolution.
* @return {ol.Coordinate} Offset.
*/
ol.renderer.dom.TileLayer.prototype.getTileOffset_ = function(z, resolution) {
var tileLayer = this.getLayer();
var tileSource = tileLayer.getTileSource();
var tileGrid = tileSource.getTileGrid();
var tileOrigin = tileGrid.getOrigin(z);
var offset = new ol.Coordinate(
Math.round((this.origin.x - tileOrigin.x) / resolution),
Math.round((tileOrigin.y - this.origin.y) / resolution));
return offset;
};
/**
* Get rid of all tiles that weren't drawn in the most recent rendering.
* @param {Object.<number, Object.<string, ol.Tile>>} tilesDrawnByZ Tiles just
* rendered.
* @private
*/
ol.renderer.dom.TileLayer.prototype.removeExtraTiles_ =
function(tilesDrawnByZ) {
var key, tileCoord, tilesDrawn, tile;
for (key in this.renderedTiles_) {
tileCoord = ol.TileCoord.createFromString(key);
tilesDrawn = tilesDrawnByZ[tileCoord.z];
if (!(tilesDrawn && key in tilesDrawn)) {
tile = this.renderedTiles_[key];
delete this.renderedTiles_[key];
goog.dom.removeNode(tile.getImage(this));
}
}
};
/**
* @param {goog.events.Event} event Tile change event.
* @private
*/
ol.renderer.dom.TileLayer.prototype.handleTileChange_ = function(event) {
var tile = event.target;
goog.asserts.assert(tile.getState() == ol.TileState.LOADED);
var tileCoord = tile.tileCoord;
if (tileCoord.z === this.renderedZ_) {
var key = tileCoord.toString();
delete this.loadingTiles_[key];
}
var loaded = true;
for (var key in this.loadingTiles_) {
loaded = false;
break;
}
if (loaded) {
var z = this.renderedZ_;
for (var key in this.renderedTiles_) {
tileCoord = ol.TileCoord.createFromString(key);
if (tileCoord.z !== z) {
tile = this.renderedTiles_[key];
delete this.renderedTiles_[key];
goog.dom.removeNode(tile.getImage(this));
}
}
}
};
/**
* Remove all loading tiles that have been appended.
* @private
*/
ol.renderer.dom.TileLayer.prototype.removeLoadingTiles_ = function() {
for (var key in this.loadingTiles_) {
var tile = this.loadingTiles_[key];
goog.dom.removeNode(tile.getImage(this));
delete this.loadingTiles_[key];
}
};
/**
* @inheritDoc
*/
ol.renderer.dom.TileLayer.prototype.render = function() {
var map = this.getMap();
if (!map.isDef()) {
return;
}
var mapExtent = /** @type {!ol.Extent} */ map.getRotatedExtent();
var mapResolution = /** @type {number} */ map.getResolution();
var resolutionChanged = (mapResolution !== this.renderedMapResolution_);
var tileLayer = this.getLayer();
var tileSource = tileLayer.getTileSource();
var tileGrid = tileSource.getTileGrid();
// z represents the "best" resolution
var z = tileGrid.getZForResolution(mapResolution);
if (z != this.renderedZ_) {
// no longer wait for previously loading tiles
this.removeLoadingTiles_();
}
/**
* @type {Object.<number, Object.<string, ol.Tile>>}
*/
var tilesToDrawByZ = {};
tilesToDrawByZ[z] = {};
var tileRange =
tileGrid.getTileRangeForExtentAndResolution(mapExtent, mapResolution);
// first pass through the tile range to determine all the tiles needed
tileRange.forEachTileCoord(z, function(tileCoord) {
var tile = tileSource.getTile(tileCoord);
if (goog.isNull(tile)) {
// we're outside the source's extent, continue
return;
}
var key = tile.tileCoord.toString();
if (tile.getState() == ol.TileState.LOADED) {
tilesToDrawByZ[z][key] = tile;
return;
} else {
if (!(key in this.loadingTiles_)) {
goog.events.listen(tile, goog.events.EventType.CHANGE,
this.handleTileChange_, false, this);
this.loadingTiles_[key] = tile;
tile.load();
}
// TODO: only append after load?
tilesToDrawByZ[z][key] = tile;
}
/**
* Look for already loaded tiles at alternate z that can serve as
* placeholders until tiles at the current z have loaded.
*
* TODO: make this more efficent for filling partial holes
*/
tileGrid.forEachTileCoordParentTileRange(
tileCoord,
function(altZ, altTileRange) {
var fullyCovered = true;
altTileRange.forEachTileCoord(altZ, function(altTileCoord) {
var tileKey = altTileCoord.toString();
if (tilesToDrawByZ[altZ] && tilesToDrawByZ[altZ][tileKey]) {
return;
}
var altTile = tileSource.getTile(altTileCoord);
if (!goog.isNull(altTile) &&
altTile.getState() == ol.TileState.LOADED) {
if (!(altZ in tilesToDrawByZ)) {
tilesToDrawByZ[altZ] = {};
}
tilesToDrawByZ[altZ][tileKey] = altTile;
} else {
fullyCovered = false;
}
});
return fullyCovered;
});
}, this);
/** @type {Array.<number>} */
var zs = goog.array.map(goog.object.getKeys(tilesToDrawByZ), Number);
goog.array.sort(zs);
var fragment = document.createDocumentFragment();
var altFragment = document.createDocumentFragment();
var newTiles = false;
var newAltTiles = false;
for (var i = 0, ii = zs.length; i < ii; ++i) {
var tileZ = zs[i];
var tilesToDraw = tilesToDrawByZ[tileZ];
var tileOffset = this.getTileOffset_(tileZ, mapResolution);
for (var key in tilesToDraw) {
var tile = tilesToDraw[key];
var tileCoord = tile.tileCoord;
var pixelBounds = tileGrid.getPixelBoundsForTileCoordAndResolution(
tileCoord, mapResolution);
var img = tile.getImage(this);
var style = img.style;
var append = !(key in this.renderedTiles_);
if (append || resolutionChanged) {
style.left = (pixelBounds.minX - tileOffset.x) + 'px';
style.top = (-pixelBounds.maxY - tileOffset.y) + 'px';
style.width = pixelBounds.getWidth() + 'px';
style.height = pixelBounds.getHeight() + 'px';
}
if (append) {
this.renderedTiles_[key] = tile;
style.position = 'absolute';
if (tileZ === z) {
goog.dom.appendChild(fragment, img);
newTiles = true;
} else {
goog.dom.appendChild(altFragment, img);
newAltTiles = true;
}
}
}
}
if (newAltTiles) {
var child = this.target.firstChild;
if (child) {
goog.dom.insertSiblingBefore(altFragment, child);
} else {
goog.dom.appendChild(this.target, altFragment);
}
}
if (newTiles) {
goog.dom.appendChild(this.target, fragment);
}
this.renderedZ_ = z;
this.renderedMapResolution_ = mapResolution;
this.removeExtraTiles_(tilesToDrawByZ);
};